Stanford trained physician Dr. Larry Weiss working in his lab at the CleanWell office in San Francisco, California, on Friday, December 21, 2012. CleanWell creates soaps, hand sanitizers, disinfectants, fabric deodorizers and bathroom cleaners leaving out triclosan, a chemical widely used in antibacterial hand soaps. The FDA proposed banning triclosan in the 1970's.

CleanWell's hand soaps promise to slay germs, and foam and ooze — just as soap should.

But unlike many antibacterial soaps, the ones from this young San Francisco company and a growing number of other manufacturers lack a potentially harmful chemical: triclosan.

Triclosan was created more than 40 years ago as a surgical scrub for hospitals. Now it appears in soaps, detergents, skin cleansers, deodorants, toothpastes and dishwashing liquids. It is so widespread that it has been detected in three-fourths of Americans over age 5, according to a survey from the Centers for Disease Control and Prevention.

But a mounting number of scientific studies paint a troubling portrait of triclosan. It has been shown to disrupt reproductive hormone activity and brain cell signaling, hinder muscle function and bring on allergies.

Triclosan's effectiveness as an antibacterial agent is also questionable. A U.S. Food and Drug Administration panel has conceded that soap with triclosan is no better against bacteria than hand-washing with plain soap and water.

The FDA is reviewing the safety of triclosan, and the National Resources Defense Council has filed a lawsuit to force the agency to publish its findings. They were supposed to become public in winter 2012, but have not yet.

“The toxicology and issues around triclosan have been around for years. Nothing has really happened,” said Dr. Larry Weiss, CleanWell's co-founder and chief scientific officer. “But consumers are starting to read labels and ask questions and then make buying decisions.”

CleanWell was formed after Conor DeAth, a Canadian boy, was born with a weak immune system. To protect him, his parents searched for household cleaning liquids without harsh chemicals.

But when the family could not find any, they invented a formula of their own. Its main ingredient is thyme oil, which company leaders say works by disabling the energy supply that bacteria need to develop.

Their recipe was sold and rebranded as CleanWell, which launched its first hand sanitizers in 2007. It now has 30 products in 5,500 stores nationwide. The company plans to start selling fabric deodorizers and disinfecting sprays and wipes nationally this month.

CleanWell's green-minded message is resonating with customers, and businesses are noticing, Weiss said.

Colgate-Palmolive has removed triclosan from its Palmolive antibacterial dish liquid and Softsoap liquid hand soap. But the compound remains in Colgate toothpaste as a gingivitis-fighting ingredient approved by the FDA.

An FDA spokeswoman said the agency was committed to releasing its findings on the safety of triclosan “as soon as possible,” but did not specify a time.